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Abstract:

An electronic register device for recording movements of the lower jaw of
a person relative to the upper jaw of the person, the device having a
bite fork for recording a position of the upper jaw relative to reference
points on the head of the person, wherein the bite fork is designed to
receive a plastic compound for recording an impression of the dentition
of the upper jaw

Claims:

1. Electronic register device for recording movements of the lower jaw of
a person relative to the upper jaw of the person, the register device
comprising: a bite fork for recording a position of the upper jaw
relative to reference points on the head of the person, wherein the bite
fork is designed to receive a plastic compound for recording an
impression of the dentition of the upper jaw, a lower-jaw attachment for
recording movements of the lower jaw relative to the upper jaw, and a
reference body, wherein the reference body can be connected in a fixed
position to the bite fork, wherein the bite fork and the reference body
connected to it in a fixed position are designed such that both the
impression and the reference body can be recorded by a scanning
procedure.

3. Electronic register device of claim 1, wherein the reference body can
alternatively be connected in a fixed position to the lower-jaw
attachment.

4. Electronic register device of claim 1, wherein the reference body has
first form-fit elements, and the bite fork has second form-fit elements,
such that, to produce the positionally fixed connection of the reference
body to the bite fork, the first form-fit elements can be brought into a
form-fit engagement with the second form-fit elements.

5. Electronic register device of claim 4, wherein the reference body can
alternatively be connected in a fixed position to the lower-jaw
attachment.

6. Electronic register device of claim 5, in which the lower-jaw
attachment has third form-fit elements, such that, to produce the
positionally fixed connection of the reference body to the lower-jaw
attachment, the first form-fit elements can be brought into another
form-fit engagement with the third form-fit elements.

8. Electronic register device of claim 7, wherein the reference body has
at least three said scan elements.

9. Electronic register device of claim 7, wherein the scan elements
protrude from a plane surface of the reference body.

10. Electronic register device of claim 7, in which at least two of the
scan elements have different shapes.

11. Electronic register device for recording movements of the lower jaw
of a person relative to the upper jaw of the person, the register device
comprising: a bite fork for recording a position of the upper jaw
relative to reference points on the head of the person, wherein the bite
fork is designed to receive a plastic compound for recording an
impression of the dentition of the upper jaw, and a lower-jaw attachment
for recording movements of the lower jaw relative to the upper jaw,
wherein the bite fork has a first reference body connected in a fixed
position to the rest of the bite fork, and the lower-jaw attachment has a
second reference body connected in a fixed position to the rest of the
lower-jaw attachment, wherein the bite fork is designed in such a way
that both the impression and also the first reference body can be
recorded by a scanning procedure.

13. Electronic register device of claim 11, wherein the first reference
body and the second reference body each have several pin-shaped or
hemispherical scan elements.

14. Electronic register device of claim 13, wherein the reference body
has at least three said scan elements.

15. Electronic register device of claim 13, wherein the scan elements
protrude from a plane surface of the reference body.

16. Electronic register device of claim 13, in which at least two of the
scan elements of the first reference body have different shapes and/or at
least two of the scan elements of the second reference body have
different shapes.

Description:

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to an electronic register device for
recording movements of the lower jaw of a person relative to the upper
jaw of the person, which register device has a bite fork for recording a
position of the upper jaw relative to reference points on the head of the
person, wherein the bite fork is designed to receive a plastic compound
for recording an impression of the dentition of the upper jaw, and a
lower-jaw attachment for recording movements of the lower jaw relative to
the upper jaw.

[0003] 2. Related Technology

[0004] To produce tooth replacements such as crowns and bridges, it is
known to form models of the dentition of an upper jaw and of the
associated lower jaw from wax and to optimize the shape of these models
in an articulator, through articulation movements, until a harmonious
movement of the tooth shapes in relation to one another is obtained. This
is referred to as a functional comparison. In this way, it is
subsequently possible to avoid time-consuming grinding work in the mouth
of the patient concerned.

[0005] According to the prior art, the tooth shape optimized in the
articulator is then recorded by scanning and, in a further step, the
desired tooth replacement, for example the crown or bridge, is produced,
preferably from ceramic, using a CAD CAM milling/grinding machine and the
data recorded by the scanning procedure.

[0006] A kind of "virtual articulator" is also known. This involves
software with which a movement of the two scanned plaster models of the
upper jaw and lower jaw relative to each other can be simulated. To be
able to determine adjustment data for this virtual articulator, it is
first necessary to produce the corresponding plaster models of the
dentition of the upper jaw and lower jaw; the adjustment values then have
to be determined using these plaster models and a mechanical articulator.
This requires quite a lot of work.

[0007] WO 2007/020091 A1 discloses an electronic register device which is
sold by the applicant under the trade name "ARCUS digma" and which is
used to adjust articulators. An electronic analysis of the position of
the lower jaw can be performed with this device. In order to measure the
movements of the lower jaw relative to the upper jaw, a carrier frame is
connected in each case to the upper jaw and the lower jaw. The carrier
frame connected on the upper part of the head to the upper jaw, and
hereinafter also called the "head part," is provided with four
microphones in the form of ultrasound receivers, while the carrier frame
connected to the lower jaw, and hereinafter also called the "lower-jaw
attachment", is provided with three corresponding ultrasound
transmitters. The twelve paths between the three transmitters and the
four microphones are evaluated in respect of their changes in length
during movements of the lower jaw relative to the upper jaw. FIGS. 2A,
2B, 2C, and 2D show sketches of the lower-jaw attachment from different
perspectives.

[0008] The head part includes a base element with support elements for
supporting the head part on the head of the person concerned or of a
patient. These support elements can in particular comprise two rearward
bearing elements, which are designed to rest in the area of the two ears,
and a nose support, which is designed to rest on the upper nose.

[0009] Moreover, the known electronic register device ARCUS digma includes
a bite fork, which serves to record the position of the dentition of the
upper jaw relative to the auditory canals. FIGS. 1A, 1B, 1C, and 1D show
sketches of the bite fork from different perspectives.

SUMMARY OF THE INVENTION

[0010] The invention provides a system by which tooth replacements, for
example crowns and bridges, can be produced more easily. The invention
also permits improved production of drill jigs in implantology.

[0011] Accordingly, the invention provides an electronic register device
for recording movements of the lower jaw of a person relative to the
upper jaw of the person. The register device has a bite fork for
recording a position of the upper jaw relative to reference points on the
head of the person, wherein the bite fork is designed to receive a
plastic compound for recording an impression of the dentition of the
upper jaw. Moreover, the register device has a lower-jaw attachment for
recording movements of the lower jaw relative to the upper jaw. In
addition, the register device has a reference body, wherein the register
device is designed so that the reference body can be connected in a fixed
position to the bite fork, with the bite fork and the reference body
connected thereto in a fixed position being designed in such a way that
both the impression and also the reference body can be recorded by a
scanning procedure, in particular by a continuous scanning procedure.

[0012] By scanning the reference body and the impression, it is possible
to maintain or establish a relationship between the scanned impression
and the movement data recorded by the register device. In this way,
adjustment values for a virtual articulator can be determined without
having to produce plaster models of the dentition of the upper and lower
jaws.

[0013] Moreover, the register device according to the invention allows
three-dimensional data of an X-ray system to be superposed with the
movement data of the register device. This facilitates the production of
drill jigs in implantology.

[0014] The reference body preferably has first form-fit elements, and the
bite fork has second form-fit elements, such that, in order to produce
the positionally fixed connection of the reference body to the bite fork,
the first form-fit elements can be brought into a form-fit engagement
with the second form-fit elements. The positionally fixed connection
between the reference body and the bite fork can thus be produced in a
particularly simple and user-friendly manner.

[0015] The register device preferably is further designed so that the
reference body can also alternatively be connected in a fixed position to
the lower-jaw attachment.

[0016] The lower-jaw attachment preferably also has third form-fit
elements, such that, to produce the positionally fixed connection of the
reference body to the lower-jaw attachment, the first form-fit elements
can be brought into another form-fit engagement with the third form-fit
elements. The positionally fixed connection between the reference body
and the lower-jaw attachment can thus be produced in a particularly
simple and user-friendly manner.

[0017] The reference body advantageously has several, preferably at least
three, pin-shaped or hemispherical scan elements, which are preferably
designed to protrude from a plane surface of the reference body. At least
two of the scan elements preferably have different shapes.

[0018] According to another aspect of the invention, an electronic
register device is provided for recording movements of the lower jaw of a
person relative to the upper jaw of the person, the register device
having a bite fork for recording a position of the upper jaw relative to
reference points on the head of the person, wherein the bite fork is
designed to receive a plastic compound for recording an impression of the
dentition of the upper jaw. Moreover, the register device has a lower-jaw
attachment for recording movements of the lower jaw relative to the upper
jaw. The bite fork has a first reference body, which is connected in a
fixed position to the rest of the bite fork, and the lower-jaw attachment
has a second reference body, which is connected in a fixed position to
the rest of the lower-jaw attachment. The bite fork is designed in such a
way that both the impression and also the first reference body can be
recorded by a scanning procedure, in particular a continuous scanning
procedure.

[0019] The first reference body and the second reference body preferably
each have several, highly preferably in each case at least three,
pin-shaped or hemispherical scan elements, which are each preferably
designed to protrude from a plane surface of the reference body in
question.

[0020] Moreover, at least two of the scan elements of the first reference
body preferably have different shapes, and/or at least two of the scan
elements of the second reference body have different shapes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention is explained in more detail below on the basis of
illustrative embodiments and with reference to the drawings, in which:

[0022] FIGS. 1A to 1D show sketches of a bite fork from different
perspectives,

[0023] FIGS. 2A to 2D show sketches of a lower-jaw attachment from
different perspectives,

[0024]FIG. 3A shows a bite fork with a first illustrative embodiment of a
reference body according to the invention,

[0025]FIG. 3B shows a bite fork with a second illustrative embodiment of
a reference body according to the invention,

[0026] FIG. 3C shows a lower-jaw attachment with a reference body
according to the first illustrative embodiment,

[0027]FIG. 3D shows a lower-jaw attachment with a reference body
according to the second illustrative embodiment,

[0028]FIG. 4 shows a perspective view of the reference body according to
the first illustrative embodiment,

[0029]FIG. 5 shows a perspective view of the reference body according to
the second illustrative embodiment,

[0030] FIGS. 6A to 6C show further sketches of the reference body
according to the first illustrative embodiment,

[0031] FIGS. 7A to 7C show further sketches of the reference body
according to the second illustrative embodiment,

[0032]FIG. 8 shows a block diagram illustrating the use of a bite fork
with the reference body according to the first illustrative embodiment,

[0033] FIG. 9 shows a sketch illustrating reference points between an
"ARCUS digma" and an articulator, and

[0035] According to the invention, an electronic register device is
provided for recording movements of the lower jaw of a person relative to
the upper jaw of the person. The register device can have the features of
the "ARCUS digma" device mentioned in the introduction. In particular,
the register device can include a corresponding head part, which includes
a base element with support elements for supporting the head part on the
head of a patient. These support elements can in particular include two
rearward bearing elements, which are designed to rest in the area of the
two ears, for example to rest in the external auditory canals, and also a
nose support, which is designed to rest on the upper nose.

[0036] The register device furthermore includes a bite fork, which is
designed and used to record a position of the upper jaw relative to
reference points on the head of the person. As has already been mentioned
in the introduction, FIGS. 1A to 1D show sketches of a known design of a
bite fork 2 from different perspectives. The bite fork 2 is designed to
receive a plastic compound, for example wax or silicone, for recording an
impression of the dentition of the upper jaw. For this purpose, the bite
fork 2 has a receiving surface 21 for receiving the plastic compound,
wherein the receiving surface 21 has a surface normal in a direction R;
moreover, the bite fork 2 has another surface 23, the surface normal of
which likewise points in the direction R, wherein the bite fork 2 is
designed in such a way that the other surface 23 is located outside the
oral cavity of the person when the bite fork 2 is positioned for taking
the impression of the dentition of the upper jaw.

[0037] The register device further includes a lower-jaw attachment. As has
already been mentioned in the introduction, FIGS. 2A to 2D show sketches
of a known lower-jaw attachment 4 from different perspectives. The
lower-jaw attachment 4 serves for recording movements of the lower jaw
relative to the upper jaw. The lower-jaw attachment has an angled,
elongate contact area 41, which is intended to be connected, for example
by an adhesive connection, to the anterior surfaces of the front teeth of
the lower jaw. Moreover, the lower-jaw attachment has a surface 43, which
is oriented at least approximately in a plane fixed by the elongate
contact area 41 and which is located outside the oral cavity of the
person when the lower-jaw attachment 4 is connected as intended to the
teeth of the lower jaw.

[0038] The register device, in contrast to the "ARCUS digma" device, also
has a reference body. FIG. 4 shows a reference body 6 according to a
first illustrative embodiment. The register device is designed in such a
way that the reference body 6 can be connected in a fixed position, and
preferably reversibly in a fixed position, to the bite fork 2, as
indicated in FIG. 3A. In other words, the design is such that the
reference body 6 can be connected to the bite fork 2 in a defined
position relative to the latter.

[0039] In particular, a form-fit engagement can be provided for this
purpose between the reference body 6 and the bite fork 2. This permits
particularly simple handling. For this purpose, as is indicated by way of
example in FIG. 6A, the reference body 6 can have first form-fit elements
62 and, as is indicated by way of example in FIG. 1A, the bite fork 2 can
have second form-fit elements 22 which, in order to produce the form-fit
engagement, can be connected in a defined manner to the first form-fit
elements 62. The first form-fit elements 22 can be formed by at least
three engagement elements, and the second form-fit elements 22 can be
formed by correspondingly shaped and congruent openings. This permits
particularly simple handling when producing the positionally fixed
connection of the reference body 6 to the bite fork 2. FIGS. 6B and 6C
show sketches of the reference body 4 from other perspectives.

[0040] Moreover, FIG. 3A indicates a corresponding impression 10 of the
dentition of the upper jaw.

[0041] Provision is preferably made that the reference body 6, in order to
produce the positionally fixed connection, can be arranged on the other
surface 23 of the bite fork 2. For this purpose, the second form-fit
elements 22 or the openings can be formed on or in the other surface 23
of the bite fork 2.

[0042] The register device is designed in such a way that both the
impression 10 of the dentition of the upper jaw, recorded with the bite
fork 2, and also the reference body 6 can be recorded by a scanning
procedure, in particular by a scanning procedure in which the position of
the reference body 6 relative to the impression 10 can be recorded. This
is indicated diagrammatically in FIG. 8. Such a scanning procedure allows
a relationship to be established between, on the one hand, the scanned
impression 10 and, on the other hand, the movement data recorded by the
register device. In this way, adjustment values for a virtual articulator
can be determined, in particular without having to produce plaster models
of the dentition of the upper jaw and lower jaw. Moreover, the register
device according to the invention allows three-dimensional data of an
X-ray system to be superposed with the movement data of the register
device. This facilitates production of drill jigs in implantology. For
the assignment of the two systems ARCUS digma and CAD CAM or ARCUS digma
and 3D scan, the entire structural component consisting of the bite fork
2 and of the reference body 6 is scanned. The tooth impressions and on
the teeth are recorded in relation to the scanner or reference body 6 in
one scan.

[0043] The register device is preferably also designed in such a way that
the reference body 6 can also be connected in a fixed position to the
lower-jaw attachment 4, as is indicated by way of example in FIG. 3C. For
this purpose, the lower-jaw attachment 4 can advantageously have third
form-fit elements 42, particularly in the form of openings, which are
shown by way of example in FIG. 2A and which are preferably shaped
analogously to the second form-fit elements 22 or the openings of the
bite fork 2. In this way, the reference body 6 can be mounted
particularly easily either on the bite fork 2 or on the lower-jaw
attachment 4. The third form-fit elements 42 are advantageously formed on
or at the surface 43 of the lower-jaw attachment 4.

[0044] The reference body 6 advantageously has several, preferably at
least three, pin-shaped or hemispherical scan elements 64, which are
preferably designed to protrude from a plane surface 66 of the reference
body 6. The configuration is preferably such that the scan elements 64
are arranged or designed to protrude in direction R from the rest of the
reference body 6 or the plane surface 66 when the reference body 6 is
connected in a fixed position to the bite fork 2. At least two of the
scan elements 64 advantageously have different shapes. For instance, as
is indicated by way of example in FIGS. 4, 6A, and 6C, pins of different
lengths can be provided as scan elements 64.

[0045]FIG. 5 shows a reference body 8 according to a second illustrative
embodiment. This reference body 8 can have scan elements 84, which are
designed analogously to the scan elements 64 in the first illustrative
embodiment. Moreover, the reference body 8 according to the second
illustrative embodiment can have corresponding first form-fit elements 82
or engagement elements, as are indicated in FIG. 7A. The reference body 8
according to the second illustrative embodiment is shown in FIG. 3B
connected to the bite fork 2 and in FIG. 3D connected to the lower-jaw
attachment 4. FIGS. 7B and 7C show other views of the reference body 8
according to the second illustrative embodiment.

[0046] FIG. 9 shows an assignment of reference points between the
electronic register device and an articulator. A corresponding system of
coordinates is shown in sketch form in FIG. 10.

[0047] As an alternative to the above-described reference body 6 or 8,
provision can be made that the bite fork of the electronic register
device has a first reference body, which is connected in a fixed position
to the rest of the bite fork, and that the lower-jaw attachment has a
second reference body, which is connected in a fixed position to the rest
of the lower-jaw attachment, wherein the bite fork is designed in such a
way that both the impression and also the first reference body can be
recorded by a corresponding scanning procedure. The first reference body
can advantageously be formed integrally with the rest of the bite fork,
and the second reference body can be formed integrally with the lower-jaw
attachment. The two reference bodies preferably each have scan elements,
which are designed analogously to the above-described scan elements 64 of
the reference body 6 according to the first illustrative embodiment.